The in-game currency of COD mobile is called CP. You can use this to buy character, gun and more items skins in the game. Here are some of the ways by which you can earn free cod points.
#1 CP Giveaways
Some of the YouTubers often have giveaways from time to time. They usually give out the cod points to the winners. All you need to do is follow the YouTuber on different platforms like Twitter or Instagram in order to win the free CP.
Swagbucks is a very popular get-paid-to website where a user needs to complete some surveys or quizzes in order to win some cash. This cash can either be converted into CP or any other means like Amazon Gift Cards etc.
#3 Google Opinion Rewards
This method is the most legitimate way of earning some rewards which can be converted into your in-game currency. You need to complete some short surveys which are quite easy and with this you can gradually collect enough rewards to buy the COD mobile skins that you wanted the most. The rewards will be converted into Google Credits which can be used to buy your COD points.
Using the COD Points
The earned COD points can be used inside the game to purchase the character skins or gun skins that the game releases in either crates, bundles, Lucky Draws or the Battle Pass. Spending money on these can seem to be quite expensive as some Lucky Draws go up to $400 at once. Hence, these methods of earing some free CP for you game seems to be a better option instead of spending your own money.